It is the curse of every naturalist. People find injured creatures and assume you can help. I seldom can. I totally lack that blend of nurse-like practicality and Franciscan patience which are required to nurture the injured wild animal back to health. Yet this poor creature was a common swift, so how could I refuse? The injury scenario looked familiar. The swift couldn't fly and immediately next to the spot where it was found was a starling squashed in the road.

Swifts and starlings are mortal enemies and compete fiercely for nests in our roof space. Last year in our village I came across a starling attacking a grounded swift. Had I not intervened it would have severely injured or killed the bird. I rescued it in my hands and watched it spiral slowly upwards, only for the starling to fly at it again and wrestle the swift to the ground in the middle of the road. I then chased it off and let the bird go a second time. It flew away rather shakily and low over neighbours' gardens and even then the starling darted directly after it and was in hot pursuit when I lost sight.

There is an excellent website on helping grounded swifts. One revelation was that one shouldn't throw them into the air, as I'd always assumed, but let them take off from your palm. It also suggested that the chances of survival are best among freshly emerged, rather overweight juveniles. Our bird, alas, never flew again. Yet it gave me strange new sensations of the species. One was the simple feeling of pity. Swifts are such consummate beings – one usually stands in awe at their reckless brilliance, at their screaming high-wire act, and forgets they occasionally fail. The other – given the scientific name, Apus apus, means "footless" – was the way the powerful little feet and sharp claws dug into my finger like a silent, achingly sad plea for help I could not give.